Agents of Erosion

Weathering and Erosion

​Weathering is the process vy which rocks are broken down into small sediments slowly over time. There are two major types of weathering.

​​Weathering

Weathering breaks rocks down into sediments, and the process of erosion moves these sediments to other locations. There are 4 agents of erosion.

​​Erosion

Sediments, rocks, and soil cannot keep moving forever. Eventually, the particles stop moving and settle where the erosional agents have carried them.

​​Deposition

Multiple Choice

what does the picture represent?

• deposition

• weathering

• erosion

• volcanos

Multiple Choice

what does this picture represent?

• deposition

• weathering

• erosion

• volcanos

Multiple Choice

what does this picture represent?

• deposition

• weathering

• erosion

• volcanos

​topography:

The surface features of a region, including how the land rises to form mountains and falls to form valleys.

​climate:

A region's typical weather conditions over a long period of time.

​words to know

Mechanical Weathering

Mechanical weathering breaks down rocks into smaller pieces, called sediments, through a physical process. This changes the shape and size of a rock, but not it's chemical composition. The two major agents are wind and water, wind can move small peices of rock, and water or ice can split rocks apart or tumble them over eachother. Other agents include living things and changing temperature.

Chemical Weathering

​ Chemical weathering breaks down a rock by changing the rock's chemical composition. Such as, when carbon dioxide in the air dissolves in rainwater, carbonic acid is formed. This can dissolve some rocks. oxygen and water can rust iron in rocks, causing the chemical compound to change.

​ But, some rocks can better withstand weathering than others. Such as quartz. When a region contains many rock types that are more resistant to mechanical weathering will take longer to break down, this is differential weathering.

Multiple Choice

What are the 3 types of weathering?

• differential weathering, volcanic weathering, and scientific weathering

• mechanical weathering, chemical weathering, and differential weathering

• ice and water weathering, fire weathering, and air weathering

• none of the above

Flowing water carries rocks, sediments, and soil downstream. The faster the water flows the bigger the particles it can carry.

Flowing Water

Glaciers rip chunks of rock out of the ground as they move across the land. The rocks and sediments caught up in a glacier are carried along the glaciers path

​​Glaciers

Wind usually carries smaller sediments that can scrape against other rocks. The scraping is called abrasion and the blowing is called deflation.

​​Wind

Gravity constanly pulls water, ice, rocks, and sediments downhill.

​​Gravity

​Erosion & It's Agents

​All of these also contribite to mechanical weathering.

The sediments, rocks, and soil cannot keep moving forever. eventually, they stop moving and settle where erosion has carried them. This is called deposition. This is also how layers are made, the oldest layers being on the bottom and the newest layers on top.

​

​Deposition

​ As a river flows into the ocean, the sediments carried by the waters begin to pile up around the rivers mouth. These create rich deposits of land, these are called deltas. Deltas make great places to farm, because of the rich nutrients in the sediments.

​River Deltas

The wind blows sand grains to form ever-changing sand dunes when the sediment is deposited. These dunes can be found along beaches and deserts where sand can be blown and deposited.

​​Sand Dunes

​ Water also deposits grains of sand that have weathered from surrounding landforms and have been carried by erosion down to rivers and deposited as shorelines along oceans. The sand accumulates on beaches and the wave action contributes to beach formation

​​Sand